UNIVERSITY   OF   CALIFORNIA 

COLLEGE   OF   AGRICULTURE 

AGRICULTURAL    EXPERIMENT   STATION 

BERKELEY,  CALIFORNIA 


POLLINATION    OF  THE 
SWEET   CHERRY 

BY 
WARREN  P.  TUFTS  AND  GUY  L.  PHILP 


BULLETIN  No.  385 

March,  1925 


UNIVERSITY  OF  CALIFORNIA  PRINTING  OFFICE 

BERKELEY,  CALIFORNIA 

1925 


POLLINATION  OF  THE  SWEET  CHERRY 

By  WARREN  P.  TUFTS  and  GUY  L.  PHILP 


In  1913  Gardner1  published  the  results  of  rather  extensive  polli- 
nation studies  with  sweet  cherries  and  showed  that  all  varieties  tested 
are  self -sterile  under  Oregon  conditions. 

Hedrick,2  in  1915,  stated  that  sweet  cherries  as  grown  in  New  York 
appear  to  be,  for  all  practical  purposes,  self-fertile.  More  recently 
Wellington3  working  in  the  same  state,  made  the  following  statement : 
1 '  Sweet  cherries  are  practically  self -sterile,  and  in  fact  many  varieties 
are  inter-sterile." 

Crane4  reports  that  all  sweet  cherries  which  have  been  tested  in 
England  are  found  to  be  self -sterile,  and  that  in  a  number  of  instances 
there  appears  to  be  incompatibility  between  varieties.  He  also  calls 
attention  to  the  fact  that  there  appear  to  be  "strains"  existing 
within  certain  of  the  cherry  varieties.  Hooper,5  another  English 
investigator,  finds  conditions  similar  to  those  reported  by  Crane. 

Florin6  reports  that  in  Sweden  numerous  Bigarreaus  and  Hearts 
are  practically  self-sterile  and  therefore  require  cross-pollination  to 
set  fruit. 

These  facts,  together  with  reports  of  crop  failure  in  many  cherry 
orchards  in  different  sections  of  California,  indicated  the  need  of 
accurate  information  on  this  subject  and  led  the  writers  to  conduct 
rather  extensive  experiments  during  the  years  1916,  1917,  1918,  1919, 
1920,  1922,  1923,  and  1924.  The  work  has  yielded  some  interesting 
results,  which  are  presented  in  this  paper.  The  data  secured  do  not 
permit  the  drawing  of  final  conclusions,  so  that  it  is  essentially  a 
progress  report. 

PROBLEMS  OF  SWEET  CHERRY  POLLINATION 

In  planning  the  work,  the  writers  had  in  mind  the  differences  of 
altitude,  climate,  and  soil,  that  exist  in  various  parts  of  California 
and  have  attempted  to  answer  the  following  questions  for  these 
various  conditions ; 

1.  Will  sweet  cherry  varieties,  when  planted  in  solid  blocks,  i.e., 
without  pollinizers,  be  commercially  profitable?  If  so,  the  varieties 
may  be  classed  as  self -fertile ;  if  unprofitable,  then  they  should  be 
classed  as  self -sterile.* 


*The  writers  prefer  the  terms  lt barren' '  and  - 'fruitful' '  as  explained  by 
Kraus  in  the  Journal  of  Heredity,  Vol.  6,  No.  12,  pp.  549-557,  1915,  rather  than 
the  inexact  terms  "sterile"  and  "fertile."  The  latter  terms  have  been  used 
in  this  paper  because  the  general  public  is  more  familiar  with  these  expressions. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

2.  If  cherry  varieties  are  self -sterile,  what  varieties  may  be  planted 
together  to  produce  profitable  crops?  This  is  a  question  of  inter- 
fertility. 


S-X^NXvGX^t 


'"Coo  TcLV 


^oo^e   S^C&cu, 


o  \w  cx'b  cuAtcxA^cL 


Fig.  1. — Showing  the  different  stages  of  bloom  from  a  pollination  standpoint. 
(1)  Immature;  (2)  Too  far  advanced  (several  petals  removed  to  show  flower 
structure);  (3)  Proper  stage  for  emasculation;  (4)  Emasculated. 


Bulletin  385]         pollination  of  the  sweet  cherry  5 

3.  When   planting  inter-fertile   varieties  together   the   following 
points  should  always  be  considered  in  selecting  the  pollinizers: 

(a)   Coincidence  of  bloom  of  pollinizer  with  that  of  the  variety  to 
be  pollinated. 


Fig.  2. — Typical  branch  for  emasculation.     Note  the  large  percentage  of 
blossoms  at  the  proper  stage  of  maturity  for  emasculation. 


6  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

(b)  Germinability  of  pollen  produced  by  the  pollinizer. 

(c)  Amount  of  pollen  produced  by  pollinizer. 

(d)  Commercial  value  of  pollinizer. 

(e)  Succession  of  ripening  for  convenience  of  harvesting. 


ORGANIZATION  OF  THE  WOEK 

The  methods  employed  were  those  commonly  used  in  cross-polli- 
nation experiments.  The  work  consisted  in  first  removing  the  stamens 
and  then  applying  the  pollen  desired  (figs.  1  and  2).  Exact  counts  of 
the  artificially  pollinated  flowers  were  made  and  the  fruits  resulting 
from  them  counted  at  harvest. 

Experiments  were  conducted  at  Davis  and  Vacaville  in  1916-1920, 
at  Watsonville  in  1916,  at  San  Leandro  in  1917,  at  Santa  Clara  in 
1920,  in  the  Occidental  district  of  Sonoma  County  in  1922  and  1923, 
and  in  Placer  County  in  1924.  In  these  experiments  about  67,000 
blossoms  were  self-pollinated,  300,000  cross-pollinated,  and  290,000 
counted  to  determine  the  normal  set. 


THE  BLOOMING  PEEIOD  OF  CERTAIN  CHERRY  VARIETIES 

Cherries  have  a  comparatively  long  blooming  period  if  the  whole 
time  from  the  opening  of  the  first  flowers  to  the  shedding  of  the  last 
blossoms  is  considered.  The  average  length  of  the  blooming  period 
for  most  varieties  is  about  two  weeks.  This  period  may  be  nearly  a 
month  in  certain  seasons.  Weather  conditions  during  and  just  pre- 
ceding the  blooming  period  have  a  marked  influence  upon  the  length 
of  the  period  of  bloom  and  also  upon  the  dates  of  blooming.  Because 
of  climatic  conditions,  the  dates  may  vary  as  much  as  three  or  four 
weeks  in  different  seasons. 

Varieties,  however,  keep  approximately  the  same  order  of  blooming 
each  season.  From  observations  in  the  Vaca  Valley  for  four  years, 
the  following  varieties  may  be  divided  into  early  and  late  bloomers. 
They  are  listed  in  their  order  of  earliness. 

Early  Bloomers  Late  Bloomers 

Advance  Rockport 

Chapman  Pontiac 

Black  Heart  Bjng 

Early  Purple  Napoleon 

Black  Tartarian  Lambert 

Burbank 

Black  Republican 


Bulletin  385]  POLLINATION   OF   THE   SWEET   CHERRY 


Under  most  conditions,  Black  Tartarian  and  Black  Republican 
overlap  the  varieties  in  the  second  column  enough  for  cross-polli- 
nizing. 

The  accompanying  chart,  figure  3,  gives  the  average  period  of 
effective  bloom  for  certain  cherry  varieties  as  grown  in  the  Vaca 
Valley  for  the  years  1917  to  1920,  inclusive.  The  term  effective 
bloom  is  used  to  designate  the  length  of  time  the  tree  is  in  conspicuous 
blossom. 


Periopot  Effective  Blcwi  or  Certain  Cherry  Varieties 

Vaca  VALLLy-CAuroR/iiA       1917  to  \320~lncL\JSNt 


ycARS 

Black  Heart  4 

Black  Tartarian  a 

Ghapma/s  4 

Apva/mch  3 

Early  Pi/rple  a 

BvRBA,NK  4 

Black  Republics  a 

Pontiac  A 

Bl/1G  4 

/Iapoleon  4 

rockport  3 

Lambert  a 


MARCH 


APRIL 


£ 

CJ 

n 

l3 

3/ 

.' 

■/ 

ft 

fl 

/ft 

11 

iv 

Fig.  3. — The  period  of  effective  bloom  of  certain  cherry  varieties,  covering 
a  period  in  nearly  all  cases  of  four  years.  The  number  of  years  averaged  is 
shown  in  a  separate  column  for  each  variety. 

ABUNDANCE  AND  VIABILITY  OF  POLLEN 

In  order  to  secure  the  best  results  under  field  conditions  from  cross- 
pollination,  it  is  necessary  to  have  varieties  which  are  good  pollen 
producers.  Fortunately,  most  cherry  varieties  are  satisfactory  in  this 
respect  as  indicated  in  table  1. 

TABLE  1 

Kelative  Abundance  of  Pollen  Produced  by  Different  Varieties 


Variety 

Pollen 
Production 

Variety- 

Pollen 
Production 

Abundance 

Medium 

Giant 

Abundant 

Advance 

Medium 

Knight 

Abundant 

Black  Heart 

Medium  to  shy 

Lambert 

Medium  to  abundant 

Black  Bepublican 

Medium 

Major  Francis 

Abundant 

Black  Tartarian 

Medium  to  abundant 

Schmidt 

Abundant 

Bing 

Medium 

Waterloo  Heart 

Abundant 

Burbank 

Medium 

Windsor 

Abundant 

Centennial 

Shy 

Wood 

Abundant 

Downer 

Abundant 

Early  Purple 

Medium  to  abundant 

8  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

To  determine  whether  the  pollen  to  be  used  was  viable,  each  sample 
collected  was  tested  in  a  12  per  cent  cane  sugar  solution.  While  cherry 
pollen  is  not  as  viable  as  the  pollen  of  some  other  fruits,  in  most  cases 
a  satisfactory  artificial  germination  was  secured.  Where  possible  a 
new  collection  of  pollen  was  made  when  satisfactory  results  were  not 
obtained  with  the  pollen  first  collected. 

There  seems  to  be  a  close  correlation  betwen  the  abundance  and 
germinability  of  the  pollen  and  the  weather  conditions  just  preceding 
and  during  the  blooming  period.  Warm,  clear  weather  is  favorable 
to  an  abundance  of  pollen  of  high  germinability,  while  cold,  cloudy 
weather  results  in  a  scant  amount  of  pollen  of  low  germinability. 

There  is  a  wide  range  in  the  percentage  of  germination  among 
different  varieties  and  also  in  the  same  variety  at  different  places  in 
the  same  and  in  different  seasons.  As  much  as  3  to  88  per  cent 
variation  in  the  pollen  of  a  single  variety  was  found  in  differnt 
localities  during  one  season. 

The  writers  secured  on  the  average  an  artificial  germination  of 
about  30  per  cent.  This  was  considered  satisfactory.  In  certain 
crosses,  a  30  to  50  per  cent  set  resulted  from  using  pollen  with  only 
a  3  to  5  per  cent  artificial  germination. 

The  preceding  figures  seem  to  indicate  that  a  low  artificial  germi- 
nation does  not  necessarily  mean  that  a  poor  set  will  result.  However, 
since  so  many  factors  determine  the  setting  of  fruit,  it  seemed  advis- 
able to  avoid  the  use  of  pollen  of  low  viability,  which  might  tend 
towards  further  confusion  in  interpretating  the  results. 

NORMAL  SET  OF  CHERRY  VARIETIES 

Immediately  after  the  petals  fall,  each  flower  begins  to  form  a 
fruit.  During  the  following  two  or  three  weeks  a  certain  percentage 
of  these  young  fruits,  for  reasons  not  fully  understood,  drop  off, 
leaving  only  a  rather  low  percentage  of  the  total  number  of  original 
blossoms  to  continue  development.  It  is  quite  necessary  that  this 
drop  take  place,  as  the  tree  under  average  circumstances  would  not 
be  able  to  carry  so  many  fruits  through  to  maturity.  The  exact  factors 
determining  which  of  these  young  fruits  shall  drop  are  not  known  at 
present.  Later  in  the  season  still  another  falling  off  of  the  young 
fruits  occurs.     This  is  known  as  the  ''June  drop." 

The  expression  ''normal  set"  is  used  to  designate  the  percentage 
of  fruit  which  sets  under  normal  conditions  when  the  tree  is  left  open 
to  insect  pollination.  The  normal  set  may  be  determined  at  any  time 
up  to  the  end  of  the  season  by  counting  the  fruits  on  a  tree  and  com- 


Bulletin  385]         pollination  of  the  sweet  cherry  9 

paring  this  number  with  that  of  the  blossoms.  In  these  experiments, 
approximately,  two  thousand  blossoms  of  each  variety,  well  distributed 
over  the  trees,  were  counted  each  year  and  records  made  of  the  normal 
set  after  the  first  drop,  after  the  second  drop,  and  at  harvest  time. 

The  normal  set  is  used  for  comparison  of  the  different  crosses.  A 
study  of  the  normal  set  in  table  3  indicates  that  most  varieties  set  a 
good  crop  in  1916,  1917,  and  1920. 

A  few  varieties  failed  to  give  a  good  crop  in  these  years.  Indi- 
vidual variations  and  condition  or  vigor  of  the  trees  may  be  partly 
responsible  for  the  shortage,  though  all  the  trees  used  appeared  to  be 
moderately  vigorous  and  received  good  commercial  care. 

The  normal  set  on  these  same  trees  during  the  years  1918  and  1919 
was  far  below  the  average,  mainly  because  of  drought  and  a  heavy 
frost  during  the  blooming  period  in  1918.  It  was  also  noted  that 
there  were  few  bees  in  the  orchard  during  the  blooming  period  of 
these  years. 

SELF-POLLINATION  OF  SWEET  CHEEEIES 

During  the  years  1916  to  1924,  inclusive,  the  following  varieties 
of  sweet  cherries  were  tested  for  self -sterility :  Abundance,  Advance, 
Black  Bigarreau,  Black  Heart,  Black  Republican,  Black  Tartarian, 
Bing,  Burbank,  Burr  Seedling,  Chapman,  Centennial,  Cleveland, 
Downer,  Early  Purple,  Lambert,  Major  Francis,  Mezel,  Pontiac, 
Rockport,  Schmidt,  Napoleon  (Royal  Ann)  (fig.  4),  Waterloo  Heart, 
Windsor,  and  Wood.  In  addition  to  these  a  number  of  promising 
seedlings  and  strains  were  tested.  They  were  tested  for  from  one  to 
six  years  and  in  no  year  or  locality  did  any  variety  give  a  satisfactory 
set  of  fruit  when  self -pollinated,  as  is  shown  by  table  2.  The  Bing, 
during  the  season  of  1917,  set  a  3.5  per  cent  crop  with  its  own  pollen, 
but  the  same  year  the  normal  set  was  over  20  per  cent.  From  a  com- 
mercial standpoint,  all  sweet  cherries  thus  far  tested  under  California 
conditions  may  be  considered  as  self -sterile.  It  is  therefore  inadvisable 
to  plant  any  of  the  commercial  varieties  alone  or  in  solid  blocks. 

POLLINATION  REQUIREMENTS  OF  CERTAIN  CHERRY  VARIETIES 

The  facts  presented  in  table  3  are  based  on  the  results  obtained 
from  pollination  experiments  conducted  in  the  Vaca  Valley  during  the 
years  1916  to  1920,  inclusive. 

The  data  secured  in  other  experiments  conducted  at  Watsonville, 
San  Leandro,  Santa  Clara,  Occidental,  and  Newcastle  have  been 
omitted  because  they  would  not  in  any  way  alter  the  conclusions. 


10 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 


The  results  of  certain  crosses  are  difficult  to  analyze  and  in  some 
instances  have  been  discarded  in  the  discussion.  This  is  particularly 
true  for  the  year  1918,  when  a  severe  frost  was  largely  responsible 
for  the  poor  sets  obtained. 


Fig.  4. — Napoleon  X  Self.     No  fruit  set  on  a  branch  of  Napoleon  which  was 
pollinated  with  its  own  pollen.    A  typical  case  of  Napoleon  when  self-pollinated. 


Bulletin  385]  POLLINATION   OF   THE   SWEET   CHERRY 


11 


TABLE  2 
Self-Pollination.     Summary  for  All  Locations 


1916 

1917 

1918 

1919 

1920 

1922 

1924 

Varieties 

co 

a 

o 

co 
co 

—    CO 
<n 

6  » 

-to 

cu 

CO 

-to 
C 
tt 

o 

CU 

ft 

CO 

s 

O 

CO 

CO 

I* 

Xi  cu 

co 

6  3 

+o 

CD 
CO 

-to 

a 
cu 
o 

CO 

ft 

CO 

s 

o 

CO 
CO 

■3*3 

—    CD 
CO 

d  3 

-to 
<D 
CO 

-to 
CI 
O 

u 

(- 

CD 
ft 

CO 

a 

o 

CO 
CO 

X!   CD 
CO 

O  3 

-to 
O 
co 

-to 

a 

CU 

o 
cu 

ft 

CO 

a 

o 

CO 
CO 

■§* 

co 

6  3 

-to 
CU 
CO 

-to 
CI 
V 
CJ 

t-l 
cu 
ft 

CO 

a 

o 

CO 
CO 

CO 

d  3 

-to 

cu 

CO 
-to 

a 

CU 

a 

h 

cu 

ft 

CO 

a 

o 

CO 
CO 

%* 

-Q  cu 

CO 

d  3 

-to 

cu 

CO 
-to 

a 

CU 

a 

cu 

ft 

429 

0  0 

Advance  .. 

2039 
1053 

0.0 
3.5 

2159 
665 

0.5 
0.1 

970 

288 

0.1 
0.3 

762 
1168 

410 

286 
1395 
1827 

368 

0.7 
0.5 
0.9 
2.0 
0.5 
0.9 
1.6 

Bing 

533 

0.2 

986 

0.0 

Black  Heart 

883 
2536 
5060 

0.0 
0.3 
0.0 

432 

872 

2142 

502 

0.2 

0.1 
0.0 
0.0 

603 

519 

1056 

432 

0.0 

0.0 
0.0 
0.0 

Black  Republican 

1288 
1647 

0.0 
0.0 

429 
1181 

1.4 
0.2 

Black  Tartarian 

Burbank 

Burr  Seedling 

1015 

0.0 

645 

0.2 

Chapman.. 

1104 

0.1 

513 

0.0 

434 

1.3 

Cleveland 

1092 

0.8 

Downer.... 

304 

0  0 

Early  Purple... 

1088 
1044 

1.0 
1.2 

504 
400 

0.4 
0.0 

214 
493 

0.9 

0.0 

390 
1056 

2.3 

0.3 

Lambert 

1010 

0.5 

L.  S.  Royal  Ann 

722 

1.0 

388 

0  0 

Mezel 

1392 

3627 

1024 

586 

0.0 
1.0 
0.1 
0.3 

Napoleon 

2233 

0.0 

522 
429 
509 

0.0 

0.0 
1.3 

500 
440 

472 

0.0 
0.0 
0.0 

1547 
534 
474 

0.7 
0.0 
0.6 

2952 

0.4 

Pontiac 

Rockport 

404 

0.7 

Schmidt 

448 
321 
362 
404 

n  o 

0  3 

Windsor 

0  0 

Wood 

610 

0.0 

0  0 

The  value  of  different  pollinizers  for  each  variety  as  appears  from 
the  results  shown  in  table  3  is  as  follows : 

Advance. — Black  Tartarian  is  the  best  pollinizer  for  Advance. 
Black  Heart,  Early  Purple,  and  Chapman  are  fairly  satisfactory. 
Advance  and  Rockport  are  inter-sterile. 

Bing. — Napoleon  and  Lambert  are  inter-sterile  with  Bing".  Black 
Tartarian,  Early  Purple,  Pontiac,  and  Black  Republican  are  satis- 
factory as  pollinizers  for  Bing  and  are  recommended  in  the  order 
named.  Figure  5  shows  graphically  the  pollination  requirements  of 
the  Bing. 

Black  Heart. — Black  Tartarian,  Early  Purple,  Burbank,  and  Chap- 
man are  recommended  as  pollinizers  for  the  Black  Heart  in  the  order 
mentioned. 


12 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT   STATION 


TABLE  3 

Cross -Pollination — Interior  Valley.    University  Farm  and  Vaca  Valley 


1916 

1917 

1918 

1919 

1920 

Varieties 

No. 
blos- 
soms 
used 

Per 
cent 
set 

No. 
blos- 
soms 
used 

Per 
cent 
set 

No. 

blos- 
soms 
used 

Per 
cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

No. 
blos- 
soms 
used 

Per 
cent 
set 

Advance  {Vaca  Valley)*: 

Normal  Set 

5671 
2039 
1018 

29.3 
0.0 
3.8 

2302 

1093 

499 

11.2 
0.1 
0.4 

2344 
515 
392 
242 
457 
519 
748 
369 
365 

1778 
455 

7.0 
0.2 
6.0 
0.0 
8.0 
3.0 
10.5 
5.4 
0.0 

10.0 
0.0 

2321 
456 
494 

14.6 

xSelf 

0.0 

x  Black  Heart  (Vaca  Valley) 

21.0 

x  Black  Republican  (Alamo) 

x  Black  Tartarian  (Watson) 

289 

15.9 

481 
514 
535 
564 
390 

2650 

1066 

550 

576 

0.0 
0.0 
0.0 
0.0 
0.0 

9.7 
0.0 
8.3 
4.6 

480 
517 
732 
522 
493 

2510 
306 
412 
447 
548 
559 
552 

24.0 

x  Burbank  (Vaca  Valley) 

3.4 

x  Chapman  (Alamo) 

1029 
1047 

5.4 

4.5 

8.4 

x  Early  Purple  (Watson) 

20.0 

x  Rockport  (Payne) 

0.0 

Advance  (Watson): 

Normal  Set 

34.0 

xSelf 

1.7 

x  Black  Heart  (Vaca  Valley) 

16.2 

x  Black  Tartarian  (Watson) 

337 
269 
292 
874 
366 
358 

6512 

288 

0.9 
2.0 
0.4 
2.2 
0.2 
0.0 

4.0 
0.3 

19.0 

x  Burbank  (Vaca  Valley) 

1.6 

x  Chapman  (Alamo) 

495 
601 

10.3 
0.2 

0.7 

x  Early  Purple  (Watson) 

6.8 

x  Pontiac  (Watson) 

x  Rockport  (Payne) 

258 

2508 
394 
373 
308 
456 
264 

415 
377 
304 
436 

0.0 

12.1 
0.0 
0.5 
1.9 
0.6 
4.1 

48.1 
3.7 
0.0 

24.7 

443 

2609 
518 

0.5 

Bing  {Vaca  Valley): 

Normal  Set 

1787 
533 

7.9 
0.0 

2464 
1052 

20.6 
3.5 

35.5 

xSelf 

0.3 

x  Black  Republican  (Alamo).... 

x  Black  Republican  (Vaca  Valley).. 

970 
694 

24.8 
15.0 

508 
494 
528 

545 
514 
534 
470 

35.0 

x  Black  Tartarian  (Alamo) 

522 
513 

39.1 
58.3 

204 
169 

125 

188 
222 

0.0 
36.7 

36.0 

15.0 

0.0 

28.0 

x  Black  Tartarian  (Bassford) 

57.0 

x  Black  Tartarian  (University 
Farm) 

55.0 

x  Black  Tartarian  (Payne) 

510 

15.9 

40.0 

x  Black  Tartarian  (Watson) 

45.0 

x  Early  Purple  (Watson)... 

52.7 

x  Lambert  (Vaca  Valley)  . 

701 
211 
516 

0.1 

28.4 
0.0 

452 
495 

0.7 
29.3 

x  Mezel  (Vaca  Valley) 

x  Napoleon  (Vaca  Valley) 

352 
575 
507 

2524 
286 

0.3 

x  Pontiac  (Watson).... 

497 

55.2 

416 
433 

2662 
432 
533 
407 
537 
422 
531 
234 
263 
412 

40.3 
0.7 

15.8 
0.2 
3.9 

11.5 
5.2 
8.5 
2.4 
2.9 
0.3 
3.6 

263 
264 

1295 
603 

44.8 
0.4 

1.7 
0.0 

43.0 

x  Rockport  (Payne) 

18.5 

Black  Heart  (Vaca  Valley): 

Normal  Set 

2243 
833 

1024 
191 

22.8 

0.0 

21.8 

37.8 

39.0 

x  Self 

2.0 

x  Advance  (Watson) 

x  Black  Tartarian  (Alamo) 

432 

38.0 

327 
320 
319 
328 
306 

46.0 

x  Black  Tartarian  (Watson)... 

36.0 

x  Burbank  (Vaca  Valley).... 

50.5 

x  Chapman  (Alamo) 

551 
514 

11.9 
22.4 

404 
343 

14.3 
39.0 

35.0 

x  Early  Purple  (Watson) 

42.0 

x  Pontiac  (Watson) 

x  Rockport  (Payne) 

*  Names  in  parentheses  indicate  location  of  tree  or  source  of  pollen,  i.  e.,  Vaca  Valley  orchard, 
Watson  orchard,  Alamo  orchard,  Bassford  orchard,  Payne  orchard  and  the  University  Farm  orchard. 
The  latter  is  at  Davis;  all  the  others  in  the  Vaca  Valley  in  Solano  County. 


Bulletin  385]         pollination  of  the  sweet  cheery 


13 


TABLE  3—  (Continued) 
Cross-Pollination — Interior  Valley.    University  Farm  and  Vaca  Valley 


1916 

1917 

1918 

1919 

1920 

Varieties 

No. 
blos- 
soms 
used 

Per 

cent 
set 

No. 
blos- 
soms 
used 

Per 
cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

No. 

blos- 
soms 
used 

Per 

cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

Black  Republican  (Vaca  Valley): 

Normal  Set 

1281 
899 

22.5 

0.0 

2046 
505 

32.3 
0.0 

2581 
400 
433 

17.2 

0.2 

59.5 

1323 
519 

12.0 
0.0 

2359 
527 
583 
380 

30.3 

xSelf 

0.7 

x  Bing  (Vaca  Valley) 

1.0 

x  Black  Tartarian  (Alamo) 

750 

38.6 

611 

9.8 

50.0 

x  Black  Tartarian  (Bassford) 

509 
325 
517 

72.7 

20.6 

0.4 

452 

50.2 

x  Black  Tartarian  (Payne) 

x  Black  Tartarian  (Watson) 

x  Cleveland 

170 

21.8 

x  Early  Purple  (Watson) 

426 
739 

35.4 
35.0 

569 
330 

7.7 
0.9 

514 
389 

29.5 

x  Lambert  (Vaca  Valley) 

430 
208 

17.4 
11.5 

54.0 

x  Mezel  (Vaca  Valley) 

x  Napoleon  (University  Farm) 

405 
314 
409 

2572 
592 
521 

37.7 
16.2 
31.7 

20.8 
0.0 
0.7 

x  Napoleon  (Vaca  Valley) 

405 
394 

32.1 
4.0 

465 
530 

2059 
521 
533 

10.3 
10.4 

7.8 
1.7 
2.0 

334 

377 

2570 
457 
511 

28.0 

x  Rockport  (Payne) 

30.0 

Black  Tartarian  (Alamo): 

Normal  Set 

2832 
1030 
977 
526 
540 
503 
507 

23.1 
0.0 
7.9 

20.3 
0.0 
0.0 

12.8 

31.5 

xSelf 

3.7 

x  Advance  (Vaca  Valley) 

15.6 

x  Bing  (Vaca  Valley)... 

x  Black  Tartarian  (Bassford) 

502 

0.8 

x  Black  Tartarian  (Payne)... 

x  Black  Heart  (Vaca  Valley)  ... 

495 
541 
522 
522 

0.2 

10.9 

0.2 

9.3 

548 
510 
545 
594 

0.9 

8.0 

10.0 

13.4 

313 

458 
492 

588 

11.5 

x  Burbank  (Vaca  Valley) 

13.3 

x  Chapman  (Alamo) 

544 
539 
507 

15.6 

8.5 
0.0 

7.5 

x  Early  Purple  (Watson) 

9.6 

x  Mezel  (Vaca  Valley)... 

x  Rockport  (Payne) 

458 

3200 
510 
500 
503 

10.4 

1.4 
0.0 
1.0 

4.7 

556 

3150 
535 
531 
537 
516 
531 
490 
523 

4.0 

2.5 
0.0 
4.5 
4.4 
0.0 
5.2 
2.8 
7.2 

398 

3060 
970 
458 
483 

6.0 

Black  Tartarian  (Watson): 

Normal  Set 

14.3 

x  Self 

0.0 

x  Advance  (Vaca  Valley) 

9.3 

x  Black  Heart  (Vaca  Valley)  .. 

3.5 

x  Black  Tartarian  (Alamo)... 

x  Burbank  (Vaca  Valley).... 

329 
518 
499 
544 
503 

0.0 
6.9 
0.0 
0.5 
0.8 

529 
535 
300 

528 
497 

4.7 

x  Chapman  (Alamo) 

13.0 

x  Early  Purple  (Watson) 

2.3 

x  Pontiac  (Watson) 

12.0 

x  Rockport  (Payne) 

513 

3.3 

12.0 

Black  Tartarian  (Bassford): 
Normal  Set 

1752 
1003 
506 
522 
423 
501 
509 
533 
527 
333 
671 
518 

30.2 
0.0 

25.5 

14.0 
5.2 
7.6 
0.2 
0.0 

25.4 
6.6 
0.0 

15.8 

xSelf 

x  Advance  (Vaca  Valley) 

. 

x  Bing  (Vaca  Valley) 

x  Black  Republican  (Vaca  Valley) 

x  Black  Republican  (Watson) 

x  Black  Tartarian  (Alamo) 

x  Black  Tartarian  (Payne)... 

x  Chapman  (Alamo) 

x  Lambert  (Vaca  Valley) 

x  Mezel  (Vaca  Valley)  . 

x  Pontiac  (Payne) 

14 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


TABLE  3—  (Continued) 
Cross -Pollination — Interior  Valley.    University  Farm  and  Vaca  Valley 


1916 

1917 

1918 

1919 

1920 

Varieties 

No. 
blos- 
soms 
used 

Per 

cent 
set 

No. 
blos- 
soms 
used 

Per 
cent 
set 

No. 
blos- 
soms 
used 

Per 
cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

Black  Tartarian  (Payne): 

Normal  Set 

3541 
1058 
520 
494 
502 
552 
510 
632 

18.1 
0.0 

11.5 
7.1 
2.6 
0.0 

22.5 
1.7 

x  Self 

x  Advance  (Vaca  Valley) 

x  Bing  (Vaca  Valley) 

x  Black  Tartarian  (Alamo) 

x  Black  Tartarian  (Bass) 

x  Chapman  (Alamo) 

x  Mezel  (Vaca  Valley) 

Burbank  (Vaca  Valley): 

Normal  Set 

2679 
502 
522 
493 
501 
476 
515 

15.1 
0.0 
2.8 
1.4 
1.0 
0.8 
2.3 

1517 
432 
512 

9.8 

0.0 

10.0 

1792 
368 
375 

48.4 

x  Self 

1.6 

x  Advance  (Vaca  Valley) 

12.0 

x  Bing  (Vaca  Valley) 

x  Black  Heart  (Vaca  Valley) 

381 
501 
509 

13.6 

9.3 

23.5 

378 
345 
410 

20.4 

x  Black  Republican  (Vaca  Valley).. 

34.8 

x  Black  Tartarian  (Alamo) 

20.7 

x  Black  Tartarian  (Payne) 

394 

19.8 

x  Chapman  (Alamo) 

533 
505 

388 

2617 
513 
517 
523 

0.0 
4.1 
0.0 

10.0 
0.0 
7.3 
7.6 

440 
527 
421 

2090 
504 
502 
412 
462 
506 
436 
462 
393 

1857 
214 
346 
123 
70 
410 
423 
414 
504 
388 
403 

3749 
493 

15.7 
6.6 
6.6 

8.5 

0.0 

41.4 

32.0 

1.5 

42.0 

27.7 

2.8 

2.5 

2.9 
0.9 
12.4 
17.8 
5.4 
1.0 
5.4 
0.4 
0.0 
0.0 
0.0 

12.0 
0.0 

399 
405 
547 

2578 
334 
425 
180 
588 
580 
580 
605 
461 

2674 
390 
420 
382 

33.0 

x  Early  Purple  (Watson) 

9.8 

x  Rockport  (Payne) 

5.6 

Chapman  (Alamo): 

Normal  Set 

2330 

1104 

1019 

525 

16.4 

0.1 

10.9 

13.9 

42.0 

x  Self 

1.3 

x  Advance  (Watson) 

17.0 

x  Black  Heart  (Vaca  Valley) 

44.0 

x  Black  Republican  (Vaca  Valley).. 

17.0 

x  Black  Tartarian  (Watson) 

236 

35.6 

521 
162 
389 
431 

2180 
504 
631 
511 
524 

6.9 
1.2 
2.3 
0.4 

8.4 
0.4 
0.0 
0.0 
7.4 

43.0 

x  Burbank  (Vaca  Valley) 

11.0 

x  Early  Purple  (Watson) 

496 

12.5 

0.2 

x  Rockport  (Payne) 

6.0 

Early  Purple  ( Watson)  : 

Normal  Set 

2641 

1088 

483 

527 

29.1 
1.0 
0.5 
4.2 

26.0 

x  Self 

2.3 

x  Advance  (Watson) 

0.0 

x  Black  Heart  (Vaca  Valley) 

1.5 

x  Black  Republican  (Alamo) 

x  Black  Tartarian  (Alamo) 

350 

14.9 

382 
369 
380 
398 
487 
419 

1837 
556 

6.5 

x  Black  Tartarian  (Watson) 

531 
489 
525 

0.0 
1.6 
0.0 

1.6 

x  Burbank  (Vaca  Valley) 

5.8 

x  Chapman  (Watson) 

513 

6.6 

1.8 

x  Pontiac  (Watson) 

9.2 

x  Rockport  (Payne) 

495 

2505 
400 

0.0 

8.5 
0.0 

0.0 

Lambert  (Vaca  Valley): 

Normal  Set 

1810 
1010 

24.4 
0.5 

2594 
1044 
450 
528 
515 
501 

17.0 
1.2 
0.2 
6.8 

32.1 
5.8 

22.0 

x  Self 

0.5 

x  Bing  (Vaca  Valley)  .. 

x  Black  Tartarian  (Alamo)... 

515 

22.0 

x  Black  Tartarian  (Bassford)  .. 

x  Black  Tartarian  (Payne)  . 

x  Black  Tartarian  (University 
Farm) 

537 

11.5 

608 

18.7 

Bulletin  385]  POLLINATION    OF   THE   SWEET    CHERRY 


15 


TAGLE  3—  (Concluded) 
Cross-Pollination — Interior  Valley.    University  Farm  and  Vaca  Valley 


1916 

1917 

1918 

1919 

1920 

Varieties 

No. 
blos- 
soms 
used 

Per 
cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 

set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

No. 
blos- 
soms 
used 

Per 

cent 

set 

No. 
blos- 
soms 
used 

Per 

cent 
set 

Lambert  (Vaca  Valley) — Con. 

x  Black  Republican  (Vaca  Valley).. 

398 

4.5 

525 

40.9 

516 

18.0 

x  Mezel  (Vaca  Valley) 

500 

509 

89 

14.4 

1.4 

22.4 

x  Napoleon  (Vaca  Valley) 

556 
461 
502 

2048 
506 
506 
496 
504 
484 
452 
453 

494 
543 

482 

0.5 

x  Pontiac  (Watson) 

537 
518 

3035 
522 

3.5 

2.1 

5.9 
0.0 

534 
589 

3176 
500 
507 
494 
564 
508 
527 
450 

497 
577 
466 

44.5 

2.7 

4.5 
0.0 
0.0 
0.4 
0.5 
2.7 
35.4 
7.5 

29.9 
1.0 
0.2 

9.3 

x  Rockport  (Payne) 

11.0 

Napoleon  {Vaca  Valley): 

Normal  Set 

4251 
995 
864 
973 

1737 

7.0 
0.0 
0.0 
6.0 
0.0 

2699 
1046 
575 
564 
481 
564 
540 
480 

520 

15.1 
0.2 
0.0 

21.5 
8.7 

12.4 

30.2 
2.9 

44.8 

24.6 

xSelf 

0.4 

x  Bing  (Vaca  Valley)... 

0.5 

x  Black  Republican  (Vaca  Valley)., 
x  Black  Republican  (Watson) 

506 
546 
529 
569 
519 

531 
494 
560 

1.7 
0.9 
3.7 
10.5 
1.9 

2.4 
0.2 
0.0 

31.0 
1.4 

x  Black  Tartarian  (Alamo) 

31.0 

x  Black  Tartarian  (Bassford) 

13.0 

x  Black  Tartarian  (Payne) 

27.0 

x  Black  Tartarian  (University 

Farm) 

26.0 

x  Black  Tartarian  (Watson) 

16.0 

x  Lambert  (Vaca  Valley) 

1251 
419 

0.0 
0.0 

799 
491 
519 

0.6 

24.7 
31.4 

3.2 

x  Mezel  (Vaca  Valley) 

x  Pontiac  (Watson) 

550 
509 

2859 
429 

3.2 
1.9 

2.4 
0.0 

474 
586 

2200 
440 
476 
372 
529 
548 
406 
466 

2119 
472 
507 

12.0 
0.0 

10.0 
0.0 
25.4 
10.7 
10.7 
3.0 
22.0 
17.8 

3.8 
0.0 
0.0 

521 
492 

2538 
534 

12.0 

x  Rockport  (Payne)... 

165 

0.6 

6.3 

Pontiac  (Watson): 

1758 
519 

6.6 
0.2 

13.0 

x  Self 

0.0 

x  Bing  (Vaca  Valley) 

520 

1.7 

408 
411 
523 
139 
414 

3077 
509 
511 

6.1 
3.8 
0.9 
0.7 
13.5 

6.2 
1.3 
0.0 

428 
432 
465 

8.8 

x  Black  Republican  (Vaca  Valley).. 

17.8 

x  Black  Tartarian  (Watson)  .... 

7.7 

x  Lambert  (Vaca  Valley) 

505 
196 

11.3 
2.6 

x  Napoleon  (Vaca  Valley) 

185 

3282 
474 
496 

0.7 

Rockport  (Payne): 

11.0 

xSelf 

0.6 

2.4 

x  Bing  (Vaca  Valley)  .. 

520 

1.7 

452 
563 
530 
519 
539 
504 

5.5 
16.5 

1.3 
38.7 

6.8 
14.6 

492 
507 
504 
440 
488 
555 

5.7 

9.0 
1.0 
11.3 
0.2 
1.5 

x  Black  Republican  (Vaca  Valley) 

460 
490 
518 

7.6 

x  Black  Tartarian  (Watson)... 

1.2 

2.1 

x  Chapman  (Alamo) 

x  Early  Purple  (Watson) 

614 

0.5 

x  Lambert  (Vaca  Valley) 

505 
196 

11.3 
2.6 

x  Napoleon  (Vaca  Valley) 

497 
562 

4.0 

24.9 

411 
159 

3.6 
5.6 

510 
434 

0.8 

x  Pontiac  (Watson) 

0.7 

Black  Republican. — The  following  varieties  are  recommended  as 
pollinizers  for  the  Black  Republican:  Black  Tartarian,  Bing,  Early 
Purple,  Lambert,  and  Napoleon.  Figure  6  shows  graphically  the 
pollination  requirements  of  the  Black  Republican. 


16 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 


b\m  CHERRY  POLLINATION 

VACAVALLEy-GALir-OR/iiA     I9/6toI920  I^clvsivc 


Cross 


Percent  of  Blossoms  Maturing 

1916  1917  1918  J9I9  (920 

>      IO    20     30    40    SO     O       !0     20     30    '70     $>      O      /O     10     30     43     JO     O      /O     £0     30     -M     50       O      /£>    &     5Q    40     SO 


/Formal  Set 

x5elf 

xBlack  Republican 

xBl  ACK  TaRTARIA/H 

xCaplv  Purple 

xLambert 

x/Sapoleovm 

xPo/ITIAG 


. 

_ 

■ 

1 

L_ 

1 

^_ 

Fig.  5. — This  chart  shows  the  influence  during  the  seasons  of  1916  to  1920, 
inclusive,  of  various  kinds  of  pollen  when  applied  to  the  flowers  of  the  Bing 
variety.  Note  the  failure  to  set  fruit  when  self -pollinated;  also  the  inability 
of  the  Napoleon  and  Lambert  pollen  to  set  fruit  on  the  Bing. 

Black  Tartarian. — Chapman,  Advance,  Bing",  Pontiac,  and  Early 
Purple  are  recommended  as  pollinizers  for  Black  Tartarian  in  the 
order  named. 


BLACK  REPVBLICA^N  CHERRY  POLLINATIONS 


Vaca Valley- California      1916 to  1920  Inclusive 


Cro55 


Percent  of  Blossoms  Maturing 


AlORMAL  SET 

x5e  L  P 

xBlagk  Tartarian 

xBing 

xEarly  Pl/rple 

xLambert 

X>NaPOLEO,M 
xRoGKPORT 


19)6 

3       tO      JO     so     *0     SO 

1317                   1918                  1919 

1920 

>      t°    *0     90    *0    JO 

^^m 

^^ 

■ 

™ 

I. 

■ 

__._        — 

Fig.  6. — This  chart  shows  the  influence  during  the  seasons  of  1916  to  1920, 
inclusive,  of  various  kinds  of  pollen  when  applied  to  the  flowers  of  the  Black 
Republican  variety.     Note  the  failure  to  set  fruit  when  self-pollinated. 


BULLETIN  385]  POLLINATION    OF    THE   SWEET    CHERRY 


17 


Burbank. — Chapman,  Black  Tartarian,  Black  Republican,  and 
Black  Heart  are  satisfactory  as  pollinizers  for  the  Burbank  and  are 
listed  in  the  order  recommended. 

Chapman. — Advance,  Black  Tartarian,  and  Black  Heart  are  satis- 
factory pollinizers  for  Chapman. 

Early  Purple. — No  satisfactory  pollinizer  has  been  found  for  Early 
Purple.    Rockport  is  inter-sterile  with  Early  Purple. 

Lambert. — Black  Tartarian,  Black  Republican,  and  Pontiac  are 
recommended  as  pollinizers  for  Lambert.  Napoleon  and  Bing  are 
inter-sterile  with  Lambert. 


/NAPOLE07N  CHERRY  POLLINATIONS 

VAGAVALLty-CrtLir-OR/NIA-J9l6T0l920  /AICLV/5IVE 


Cross 


Percenl  of  Blossoms Malvring 


/SormalSqt 

XSCLP 
xBl/16 

xBlack  Repvslican 
xBlack  Tartarian 
xLambcrt 

XPo/ITIAC 


1316 

0     19    ZO    SO   40    $e 

■ 

1317 

»         O      10      SO     40      iO 

■ 

1318 

>      /0     10    JO     4Q     &     t 

■ 

1913 

>     /a    zo    jo   -jo    so    . 

■ 

1920 

?       'O     iO     JO     40      JO 

■ 

NMH 

1 

^■■■^ 

1 

1 

BZB 

Fig.  7. — This  chart  shows  the  influence  during  the  seasons  of  1916  to  1920, 
inclusive,  of  various  kinds  of  pollen  when  applied  to  the  flowers  of  the 
Napoleon  variety.  Note  the  failure  to  set  fruit  when  self -pollinated;  also  the 
inability  of  the  Bing  and  Lambert  pollen  to  set  fruit  on  the  Napoleon. 

Napoleon. — Black  Tartarian,  Black  Republican,  and  Pontiac  are 
the  most  satisfactory  pollinizers  for  Napoleon.  Bing  and  Lambert  are 
inter-sterile  with  Napoleon.  Figure  7  shows  graphically  the  polli- 
nation requirements  of  the  Napoleon. 

Pontiac. — Advance,  Black  "Republican,  Lambert,  and  Napoleon 
appear  to  be  the  best  pollinizers  for  Pontiac. 

Rockport. — Burbank,  Black  Republican,  and  Pontiac  appear  to  be 
the  best  pollinizers  for  the  Rockport. 

The  following  diagram  (fig.  8)  represents  graphically  the  varietal 
requirements  of  certain  sweet  cherry  varieties.  A  square  indicates 
crosses  which  are  inter-fertile.  A  circle  indicates  self -sterility,  or  inter- 
sterility  between  varieties,  and  the  blank  spaces  indicate  crosses  which 
are  not  recommended  or  which  have  not  been  made. 


18 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 


Piagramatig     Representation 

or-  THE 
POLLI/NATIO/H     REQIREWE/NT5 

or 

GERTAW    5WEET    CliERRy    VARIETIE5 

2;    < 
h    y    s    *    z: 
c   3    S    ?    J 

-^  cr  h    k    $ 

_^     -""     -J     >     ^ 
i    CQ    cQ[Q    tfl    Q 

-J 
IX 

> 

_J 

a 
C 

S 

i 

s      >- 

iU      0      <* 

_]     c     0 

O      ^      Cl 

cx     t-     s: 
<Z     K      <£ 

^   r?    c£ 

Apvaace 
B1/N6 

Bl.  )1eart 
BlRepvblic/vi 
^  DlTartaria/n 

^  Bv/R5A/NK 

^  Chapman 

O 

EarlyPv/rpll- 

Laoobert 

/Iapoleo/n 

Po/NTIAG 
<p  RoCKPORT 

• 

■ 

■ 

B 

• 

• 

■ 

■ 

• 

•  I 

■ 

• 

■ 

■ 

■ 

■ 

• 

■ 

■ 

■ 

■ 

■ 

■ 

■ 

■ 

■ 

■ 

• 

• 

• 

• 

■ 

• 

• 

■ 

• 

■ 

• 

"• 

■ 

■ 

■ 

■ 

■ 

• 

■ 

■ 

■ 

• 

Note :  Circ/es  Indicate  Sterility 

Sauares  indicate  Inter- Fertility 

Fig.  8. — This  chart  indicates  the  pollination  requirements  of  certain  sweet 
cherry  varieties.  The  circles  indicate  sterility,  the  squares  indicate  inter- 
fertility  and  the  blank  spaces,  crosses  which  are  not  recommended  or  which 
have  not  been  made. 


INTER-STERILITY  BETWEEN  CHERRY  VARIETIES 

One  of  the  unfortunate  conditions  existing  among  cherry  varieties 
is  the  inter-sterility  of  Napoleon,  Lambert,  and  Bing  (fig.  9).  It  is 
particularly  unfortunate  with  Napoleon  and  Bing,  since  Napoleon  is 
the  important  canning  variety  and  also  an  important  shipper,  while 
Bing  is  one  of  the  best  shipping  varieties.  Under  all  California  con- 
ditions tested  these  three  varieties  will  not  cross-pollinate  each  other ; 
i.e.,  mixed  plantings  of  them  will  not  produce  fruit  unless  the  trees 
are  within  range  of  some  other  variety  or  varieties  that  are  inter- 
fertile  with  them.  Gardner1  and  Schuster7  have  observed  the  same 
condition  existing  in  Oregon. 


Bulletin  385]         pollination  of  the  sweet  cherry 


19 


* 


vJi 


Fig.  9. — Napoleon  X  Bing.  No  fruit  set  on  a  branch  of  Napoleon  which  was 
pollinated  with  Bing  pollen.  A  typical  case  resulting  from  crossing  Napoleon 
with  Bing. 

Several  unimportant  varieties  have  also  proved  to  be  inter-sterile 
as  follows:  Advance  and  Rockport;  Early  Purple  and  Rockport. 


20 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


STEAINS  AND  VARIETIES 

It  has  been  observed  that  various  orchards  which  consist  appar- 
ently of  the  same  varieties  differ  in  the  size  of  crop  produced.  This 
fact  led  the  writers  to  try  different  trees  of  the  same  variety  as  polli- 
nizers  in  certain  crosses.    The  "sets"  obtained,  as  indicated  in  table  3, 


Fig.  10. — Napoleon  X  Black  Tartarian.  One  Napoleon  fruit  set  from  thirty- 
six  blossoms  pollinated  with  Black  Tartarian  pollen.  A  typical  cluster  resulting 
from  crossing  Napoleon  with  a  "poor  strain"  of  Black  Tartarian. 


Bulletin  385]         pollination  of  the  sweet  cherry 


21 


varied  so  greatly  that  it  was  felt  that  in  many  instances  several 
"strains"  have  been  included  under  one  varietal  name  which  more 
properly  should  be  used  to  designate  a  general  type,  e.g.,  the  Napoleon 
type,  the  Black  Tartarian  type,  etc. 

Practically  all  early,  rather  soft  black  sweet  cherries  are  called 
Black  Tartarian.     In  the  Vaca  Valley  alone,  the  writers  have  located 


Fig.  11. — Napoleon  X  Black  Tartarian.  Sixty-two  fruit  set  from  one  hundred 
blossoms  pollinated  with  Black  Tartarian  pollen.  A  typical  cluster  of  Napoleon 
resulting  from  crossing  Napoleon  with  a  "good  strain"  of  Black  Tartarian. 


22  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT   STATION 

five  different  strains  of  Black  Tartarian  which,  the  same  season  on  the 
same  Napoleon  tree,  set  from  less  than  3  per  cent  (entirely  unsatis- 
factory) to  40  per  cent  of  fruit  with  artificial  pollination.  See 
figures  10  and  11. 

In  the  case  of  Black  Republican,  under  the  same  conditions  noted 
above,  two  strains  have  been  observed. 

The  majority  of  the  Napoleon  trees  in  various  orchards  appear  to 
be  true  to  variety.  However,  everyone  familiar  with  this  so-called 
variety  has  observed  considerable  variation  in  the  time  of  bloom  and 
of  ripening,  and  in  the  characters  of  fruit  of  different  trees.  The 
writers  are  of  the  opinion  that  the  Napoleon  should  be  considered  a 
"type"  rather  than  a  true  variety. 

This  condition  is  not  peculiar  to  California  cherry  orchards  but 
seems  to  be  general  in  the  Pacific  Coast  states.  Professor  C.  E. 
Schuster*  of  Oregon  Agricultural  College  says :  '  *  I  have  come  to  the 
conclusion  that  here  is  no  definite  variety  in  many  cases  with  our 
sweet  cherries,  but  rather  a  'type.'  Professor  Gardner's  work1  was 
followed  in  many  cases  with  interest  by  the  growers  in  this  state,  and 
in  several  instances  his  recommendations  were  followed  in  planting 
out  orchards.  Within  the  last  year  or  two,  I  have  visited  several  of 
those  orchards  that  followed  his  recommendations  as  to  varieties  to 
use  for  pollination  work  and  those  orchards  are  getting  practically  no 
results  today.  The  one  variety  that  has  given  us  more  trouble  than  all 
others  put  together,  without  question,  is  the  Long  Stem  Waterhouse. 
As  soon  as  that  variety  was  recommended  for  pollination  purposes, 
anything  that  had  a  long  stem  to  it,  qualified  as  a  Long  Stem  Water- 
house.  ' ' 

The  above  quotation  indicates  that  the  results  obtained  in  Oregon 
are  similar  to  those  secured  in  California.  In  a  recent  report  Crane4 
of  England  writes  as  follows:  "Confusion  was  found  in  the  nomen- 
clature of  cherry  varieties,  i.e.,  three  distinct  strains  of  Black  Tar- 
tarian have  already  been  discovered. ' ' 

For  most  cherry  varieties  there  are  fairly  satisfactory  pollinizers. 
It  should  be  remembered  that  there  are  "strains"  and  "types"  of 
cherries.  While  the  writers  feel  that  in  many  instances  the  recom- 
mended crosses  will  set  satisfactory  crops  there  perhaps  will  be  cases 
where  growers  may  unfortunately  secure  incompatible  "strains"  or 
"types."  The  data  presented  in  table  3  clearly  show  that  the  pollen 
of  one  variety  used  to  pollinate  another  variety  in  the  same  orchard 
will  not  necessarily  pollinate  what  is  called  the  same  variety  in  other 


Correspondence  with  the  authors,  1923. 


Bulletin  385]         pollination  of  the  sweet  cherry  23 

orchards.  The  only  safe  way  to  know  whether  two  varieties  will  cross 
pollinate  is  actually  to  test  them.  If  these  varieties  are  satisfactory 
and  a  grower  desires  to  plant  them,  he  should  propagate  from  scion 
wood  secured  from  trees  of  these  respective  varieties,  the  fruitfulness 
of  which  is  definitely  known.  Orchard  observation  is  not  always  a 
safe  guide.  One  instance  called  to  the  writers'  attention  in  the 
Occidental  district  of  Sonoma  County  will  show  the  difficulty  of 
depending  altogether  on  orchard  observation.  A  certain  orchard, 
supposedly  of  Napoleons  and  Bings,  had  been  yielding  such  good 
crops  that  the  neighboring  orchardists  took  it  for  granted  that  the 
Bings  were  pollinating  the  Napoleons.  Several  of  them  secured  Bing 
scion  wood  to  top-work  into  their  own  Napoleon  orchards  for  polli- 
nation purposes.  It  was  later  discovered  that  there  was  scattered 
through  the  orchard  in  question  another  variety,  very  similar  to  the 
Napoleon,  which  one  season's  experimental  work  showed  to  be  a 
pollinizer  of  not  only  the  Napoleon  but  also  the  Bing.  This  variety 
has  been  locally  called  a  Long  Stem  Royal  Ann. 


POLLINIZING  AGENCIES 

After  having  planted  inter-fertile  varieties,  the  orchardist  should 
by  all  means  provide  an  agency  for  the  transfer  of  the  pollen  from  the 
trees  of  one  variety  to  those  of  another.  Since  the  common  honey  bee 
is  by  far  the  best  carrier  of  pollen,  it  will  pay  the  grower  to  keep 
bees,  although  he  may  not  care  to  go  into  the  honey  business.  Bees, 
however,  are  a  very  profitable  side  line  for  the  orchardist,  especially 
if  alfalfa  fields  are  available  after  the  blooming  season  of  fruit  has 
passed.  About  one  hive  of  bees  to  an  acre  of  bearing  orchard  should 
be  provided.  Preferably  the  hives  should  be  scattered  as  widely  as 
possible  throughout  the  orchard  during  the  blooming  season.  Experi- 
ments and  experience  have  shown  that  little  reliance  can  be  placed  on 
the  efficacy  of  wind  and  insects,  or  agencies  other  than  the  honey  bee, 
in  effecting  the  transfer  of  pollen  from  tree  to  tree,  or,  indeed,  from 
flower  to  flower. 

Eliminating  from  consideration  all  conditions  which  may  influence 
the  fruitfulness  of  an  orchard  except  those  occurring  at  blooming  time, 
it  may  be  said  that  the  set  is  largely  influenced  by  weather  conditions. 
Cold  weather,  besides  killing  the  blossoms  or  lowering  the  vitality  of 
the  pollen,  often  prevents  bees  from  working.  The  same  is  true  if 
cloudy,  wet  or  windy  weather  prevails.  For  their  best  work  bees 
demand  clear,  warm,  and  quiet  days,  and  since  the  weather  at  the 


24  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

time  cherries  bloom  is  often  very  unsettled,  it  is  readily  seen  that  the 
blooming'  period  of  the  various  pollinizing  varieties  should  overlap 
perhaps  a  week,  in  order  that  there  may  be  one  or  two  days  at  least 
when  the  weather  will  be  favorable  for  insect  activity. 

It  is  rather  interesting"  to  note  that  insects,  bees  in  particular, 
are  responsible  for  the  pollen  transfer  in  all  cases,  for  such  fruits  as 
the  pear,  almond,  and  cherry.  In  these  fruits,  no  wind  pollination 
takes  place. 

The  writers  have  tested  the  question  of  wind  pollination  quite 
thoroughly.  In  the  emasculation  of  cherry  blossoms,  it  has  been 
found  that  the  stamens  are  most  easily  removed  by  cutting  through 
the  calyx  and  removing  it  with  the  stamens  and  petals  attached.  No 
flowers  emasculated  as  described  above  will  set  fruit  unless  artificially 
pollinated.  In  other  words,  the  insects  will  not  visit  flowers  from 
which  the  petals  have  been  removed,  nor  is  pollen  blown  on  the  stigmas 
by  wind,  as  is  shown  by  the  following  figures.  The  following  sets 
may  be  compared  with  the  normal  sets  in  table  3  as  a  check. 

In  1920,  6445  emasculated  cherry  blossoms  from  nine  different 
varieties  in  five  different  orchards  set  27  fruits,  a  set  of  0.4  per  cent. 

In  1922,  4598  emasculated  cherry  blossoms  from  five  different 
varieties  in  six  different  orchards  set  1  fruit,  a  set  of  0.02  per  cent. 

In  1922,  1221  Napoleon  blossoms  from  three  different  orchards  set 
1  fruit,  a  set  of  0.08  per  cent. 

In  1924,  3513  emasculated  cherry  blossoms  from  four  different 
varieties  set  20  fruits,  a  set  of  0.5  per  cent. 

AEEANGEMENT  OF  THE  OECHAED  FEOM  A  POLLINATION 

STANDPOINT 

In  planting-  an  orchard  it  is  desirable  to  have  at  least  every  sixth 
and  preferably  every  fourth  row  of  a  pollinizing  variety.  For  con- 
venience in  harvesting,  it  is  best  to  plant  two  rows  of  one  kind,  then 
two  rows  of  the  pollinizing  variety,  and  so  on ;  or  if  it  is  desired  to 
have  more  of  one  variety  than  another,  four  rows  of  the  favored 
variety  and  then  two  rows  of  the  pollinizer,  and  repeat.  For  various 
reasons,  it  is  often  desirable  to  reduce  the  number  of  pollinizing  trees 
to  the  minimum.  Under  these  circumstances,  one  tree  in  eight  is 
strongly  recommended. 

In  planting  one  tree  of  the  pollinizer  to  seven  or  eight  of  the  main 
variety,  the  pollinizer  should  be  placed  as  every  third  tree  in  every 
third  row,  as  shown  in  the  diagram  below,  the  ''0"  in  each  case 
representing  a  pollinizer  tree : 


BULLETIN  385]  POLLINATION    OF    THE   SWEET    CHERRY 


25 


0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

On  account  of  the  seriousness  of  the  pollination  problem  with  sweet 
cherries,  it  is  felt  that  under  certain  conditions  it  may  be  advisable 
to  graft  over  a  branch  on  each  tree  to  a  pollinizer.  It  is  realized  that 
this  would  tend  toward  confusion  in  harvesting ;  however,  the  problem 
is  so  serious  that  the  grower  could  well  afford  to  forget  the  commercial 
value  of  the  fruit  on  the  pollinizing  branch. 

The  above  suggestion  is  made  primarily  for  the  orchardist  who 
has  mature  trees  which,  because  of  the  planting  of  solid  blocks  of  one 
variety  or  inter-sterile  varieties,  have  failed  to  produce  fruit.  Some 
relief  may  be  obtained  during  the  years  while  waiting  for  the  trees 
grafted  over  to  pollinizing  varieties  to  come  into  bearing,  by  cutting 
off  branches  of  pollinizing  varieties,  placing  the  cut  ends  in  vessels 
of  water  and  distributing  them  throughout  the  orchard  during  the 
blooming  period.  Such  limbs  will  live  for  several  days  and  continue 
to  bloom,  forming  pollen  for  the  bees  to  transfer  to  the  sterile  variety. 


SUMMAEY  OF  CHERRY  POLLINATION 

1.  Sweet  cherry  varieties  may  be  roughly  divided  into  two  classes, 
early  bloomers  and  late  bloomers,  when  the  period  of  their  effective 
bloom  is  considered. 

2.  All  sweet  cherry  varieties  tested  produce  satisfactory  amounts 
of  pollen  and  under  most  conditions  have  a  satisfactory  artificial 
germination  in  a  12  per  cent  sugar  solution. 

3.  All  sweet  cherry  varieties  thus  far  tested  have  proved  self- 
sterile,  including  Abundance,  Advance,  Black  Bigarreau,  Black  Heart, 
Black  Republican,  Black  Tartarian,  Bing,  Bur  bank,  Burr  Seedling, 
Chapman,  Centennial,  Cleveland,  Downer,  Early  Purple,  Lambert, 
Long  Stem  Royal  Ann,  Major  Francis,  Mezel,  Napoleon  (Royal  Ann), 
Pontiac,  Rockport,  and  Wood. 

4.  Napoleon,  Lambert  and  Bing  are  inter-sterile.  Advance  and 
Rockport  are  inter-sterile.  Early  Purple  and  Rockport  are  inter- 
sterile. 


26  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

5.  Results  indicate  that  many  so-called  varieties  of  cherries  are  in 
fact  types.    This  is  especially  true  from  a  pollination  standpoint. 

6.  It  will  be  necessary  to  isolate  inter-fertile  ' '  strains ' '  of  the  more 
important  kinds  of  cherries  and  propagate  from  these  before  uni- 
formly high  yielding  orchards  can  be  secured. 

7.  Pollinizing  agencies,  such  as  honey  bees,  are  necessary  to  set  a 
good  fruit  crop. 

8.  At  least  one  stand  of  bees  should  be  provided  for  each  acre  of 
orchard. 

9.  Care  should  be  taken  in  the  arrangement  of  varieties  in  the 
orchard  to  facilitate  cross-pollination  and  convenience  in  orchard 
management. 

10.  Solid  blocks  of  inter-sterile  varieties  may  be  made  fruitful  by 
grafting  in  pollinizers. 

11.  Large  limbs  of  a  pollinizer  placed  in  vessels  of  water  and  dis- 
tributed through  the  orchard  during  the  blooming  period  will  secure 
a  set  of  fruit  while  inter-fertile  grafts  are  coming  into  bearing. 

RECOMMENDATIONS 

Probably  the  safest  way  to  obtain  a  high  producing  sweet  cherry 
orchard  at  the  present  time  is  to  plant  a  seedling  orchard  (Mazzard 
or  Mahaleb),  and  later  top-work  the  branches  with  scions  taken  from 
desirable  strains. 

While  the  seedling  trees  are  growing,  the  orchardist  should  visit 
high  yielding  plantings  during  the  harvesting  season  and  study  the 
varieties.  It  will  be  necessary  for  him  to  determine  definitely  whether 
the  varieties  in  which  he  is  interested  are  cross-pollinating  each  other 
and  not  being  pollinized  by  chance  seedlings  or  unimportant  com- 
mercial varieties  scattered  throughout  the  orchard  under  observation. 

The  work  herein  reported  indicates  that  a  number  of  so-called 
' '  varieties ' '  are  not  true  varieties  but  rather  ' '  types ' '  consisting  of  a 
number  of  ' '  strains, ' '  some  of  which  are  good  pollinizers  while  others 
are  not.  '  I 

The  only  way  to  learn  definitely  whether  two  so-called  ' '  varieties ' ' 
will  cross-pollinate  is  by  careful  observation,  as  indicated  above,  or  by 
artificial  cross-pollination  experiments.  The  writers  hope  to  continue 
these  experiments  with  the  view  of  finding  particular  strains  of  com- 
mercial varieties  which  are  inter-fertile  and  from  which  it  will  be 
possible  to  obtain  quantities  of  scion  wood  for  future  plantings. 


Bulletin  385]         pollination  of  the  sweet  cherry  27 

An  added  advantage  of  top -working  is  the  elimination  of  serious 
bacterial  gummosis  (Bacterium  cerasi  Griffin)  infections  on  the  trunk 
and  framework  branches.  The  Mazzard  seedling  is  very  resistant  to 
gummosis.  Barss8  states:  "Mahaleb  seedlings  appear  to  be  immune." 
Howard's9  observations  of  thousands  of  Mahaleb  seedling  trees  failed 
to  show  a  single  infection  of  gummosis.  It,  therefore,  seems  that  the 
grower  can  use  one  or  the  other  of  these  stocks,  according  to  the  soil 
conditions. 

The  above  recommendations  necessitate  considerable  expense  to  the 
grower.  It,  therefore,  seems  advisable  to  suggest,  where  there  is  little 
danger  from  gummosis  that  the  grower  can  contract  with  a  nursery- 
man to  propagate  his  trees,  using  buds  from  the  selected  trees. 


ACKNOWLEDGMENTS 

The  writers  wish  to  express  their  appreciation  of  the  help  they  have 
received  from  the  following  persons  in  carrying  out  this  work: 

To  Messrs.  M.  N.  Wood  and  J.  L.  Stahl,  Misses  Ruth  Amesbury 
and  Edna  Russ,  and  other  members  of  the  Division  who  have  rendered 
assistance  in  the  field  and  laboratory ;  Messrs.  S.  H.  Davidson,  W.  B. 
Weidenthal,  Bruce  Hill,  C.  E.  Seibert  and  W.  S.  Mallock,  senior 
students  in  the  University  who  performed  certain  phases  of  the  work 
as  thesis  problems  and  without  whose  help  it  would  have  been  impos- 
sible to  make  so  many  crosses;  Dr.  W.  L.  Howard,  who  has  given 
service  in  suggestions  and  criticisms. 

To  the  Earl  Fruit  Company,  The  Buck  Fruit  Company,  The 
Pioneer  Fruit  Company,  H.  A.  Bassford,  and  Mrs.  L.  J.  Payne  of 
Vacaville ;  J.  D.  Copeland  of  Watsonville;  J.  W.  Anderson  of  Davis; 
A.  B.  Cory  of  San  Leandro;  H.  G.  Keesling  and  Mr.  Di  Fioro  of 
Santa  Clara;  J.  Blunden,  J.  Doty,  W.  Grinnell,  Mrs,  I.  Jonas,  J. 
McLain,  and  D.  M.  Searby  of  Sonoma  County;  and  the  Silva-Berg- 
tholdt  Nursery  Company  of  Newcastle  who  have  kindly  allowed  the 
use  of  their  orchards  for  certain  experiments  and  without  whose 
cooperation  most  of  the  work  could  not  have  been  accomplished. 


28  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


LITERATURE  CITED 

i  Gardner,  V.  R. 

1913.  A  preliminary  report  of  the  pollination  of  the  sweet  cherry.  Oregon 
Agr.  Exp.  Sta.  Bull.  116:1-40. 

2  Hedrick,  U.  P. 

1915.     The  cherries  of  New  York.  Part  II  of  the  33d  Ann.  Eept.  New  York 
Agr.  Exp.  Sta.,  p.  82. 

s  Wellington,  R. 

1923.  Self  sterility  and  self  fertility  of  fruit  varieties  grown  in  New  York. 
New  York  Agr.  Exp.  Sta.  (Geneva)  Cir.  71:1-6. 

*  Crane,  M.  B. 

1923.  Report  on  tests  of  self-sterility  and  cross-incompatibility  in  cherries 

at  the  John  Innes  Horticultural  Institution.     Jour.  Pom.  Hort. 
Sci.  3:67-84. 

s  Hooper,  C.  H. 

1924.  Notes  on  the  pollination  of  cherries  applied  to  commercial  cherry 

growing.     Jour.  Pom.  Hort.  Sci.  3:185-190. 

6  Florin,  Rudolph 

1924.  Korsbarstradens  pollinering  (pollination  of  cherries).  Meddelanden 
fran  pernamenta  kommitten  for  Fruktodlinsforsck.  Stockholm, 
Sweden,  1:1-34. 

7  Schuster,  C.  E. 

1922.     Pollination  of  the  sweet  cherry.     Oregon  Agr.  Exp.  Sta.  Cir.  27:1-3. 

(See    also    Burtner,    J.    C.      Latest    cherry    pollination    studies. 

Better  Fruit  18,  No.  2:5-6.) 
s  Barss,  H.  P. 

1918.     Bacterial  gummosis  of  stone  fruits.     Calif.  State  Dept.  Hort.  Mo. 

Bull.  7:121-136. 

s  Howard,  W.  L. 

1924.     Unpublished  data.     California  Agr.  Exp.  Sta. 


STATION  PUBLICATIONS  AVAILABLE  FOR  FREE  DISTRIBUTION 


BULLETINS 

No.  No. 

253.  Irrigation   and   Soil  Conditions  in  the  346. 

Sierra  Nevada  Foothills,  California.  347. 

261.  Melaxuma    of    the    Walnut,    "Juglans 

regia."  348. 

262.  Citrus   Diseases   of  Florida   and  Cuba  349. 

Compared  with  Those  of  California. 

263.  Size  Grades  for  Ripe  Olives.  350. 
268.  Growing  and  Grafting  Olive  Seedlings.  351. 
273.   Preliminary  Report  on  Kearney  Vine-  352. 

yard  Experimental  Drain. 

275.  The  Cultivation  of  Belladonna  in  Cali-  353. 

fornia.  354. 

276.  The  Pomegranate.  357. 

277.  Sudan  Grass 

278.  Grain  Sorghums. 

279.  Irrigation  of  Rice  in  California.  358. 

280.  Irrigation  of  Alfalfa  in  the  Sacramento 

Valley.  359. 

283.  The  Olive  Insects  of  California.  360. 

285.  The  Milk  Goat  in  California. 

286.  Commercial  Fertilizers.  361. 

287.  Vinegar  from  Waste  Fruits. 

294.   Bean  Culture  in  California.  362. 

298.   Seedless  Raisin  Grapes.  363. 

304.  A  Study  of  the  Effects  of  Freezes  on 

Citrus   in   California.  364. 

310.  Plum  Pollination. 

312.   Mariout  Barley.  366. 

813.  Pruning  Young  Deciduous  Fruit  Trees. 
317.   Selections  of  Stocks  in  Citrus  Propa-  367. 

gation. 
319.   Caprifigs  and  Caprification.  368. 

321.   Commercial  Production  of  Grape  Syrup. 

324.  Storage  of  Perishable  Fruit  at  Freezing  369. 

Temperatures.  370. 

325.  Rice  Irrigation  Measurements  and  Ex-  371. 

periments     in     Sacramento     Valley, 

1914-1919.  372. 

328.  Prune  Growing  in  California. 

331.  Phylloxera-Resistant  Stocks.  373. 

334.  Preliminary  Volume  Tables  for  Second-  374. 

Growth  Redwood. 
835.  Cocoanut   Meal    as   a   Feed   for  Dairy 

Cows  and  Other  Livestock.  375. 

336.  The   Preparation  of  Nicotine  Dust  as 

an  Insecticide.  376. 

339.  The  Relative  Cost  of  Making  Logs  from 

Small  and  Large  Timber.  377. 

340.  Control  of  the  Pocket  Gopher  in  Cali-  378. 

fornia. 

343.  Cheese  Pests  and  Their  Control. 

344.  Cold  Storage  as  an  Aid  to  the  Market- 

ing of  Plums. 


Almond  Pollination. 

The  Control  of  Red  Spiders  in  Decidu- 
ous Orchards. 

Pruning  Young  Olive  Trees. 

A  Study  of  Sidedraft  and  Tractor 
Hitches. 

Agriculture  in  Cut-over  Redwood  Lands. 

California  State  Dairy  Cow  Competition. 

Further  Experiments  in  Plum  Pollina- 
tion. 

Bovine  Infectious  Abortion. 

Results  of  Rice  Experiments  in   1922. 

A  Self-mixing  Dusting  Machine  for 
Applying  Dry  Insecticides  and 
Fungicides. 

Black  Measles,  Water  Berries,  and 
Related  Vine  Troubles. 

Fruit  Beverage  Investigations. 

Gum  Diseases  of  Citrus  Trees  in  Cali- 
fornia. 

Preliminary  Yield  Tables  for  Second 
Growth  Redwood. 

Dust  and  the  Tractor  Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in  Relation  to  Mouldy  Walnuts. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter  Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and  Large  Timber. 

The  Cost  of  Producing  Market  Milk  and 
Butterfat  on  246  California  Dairies. 

Pear  Pollination. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,    1923. 

Sun-Drying  and  Dehydration  of  Wal- 
nuts. 

The  Cold  Storage  of  Pears. 

Studies  on  the  Nutritional  Disease  of 
Poultry  Caused  by  Vitamin  A  De- 
ficiency. 


CIRCULARS 

No.  No. 

70.  Observations    on    the    Status    of    Corn  155. 

Growing  in  California.  157. 

Alfalfa.  160. 

The  Use  of  Lime  and  Gypsum  on  Cali-  161. 

fornia  Soils.  164. 

Correspondence  Courses  in  Agriculture.  165. 
117.  The    Selection    and    Cost    of    a    Small 

Pumping  Plant.  166. 

House  Fumigation.  167. 

The  Control  of  Citrus  Insects.  170. 
Afelilotus    indica    as    a    Green-Manure 

Crop  for  California.  172. 

Oidium  or  Powdery  Mildew  of  the  Vine.  173. 
Feeding  and  Management  of  Hogs. 

152.   Some  Observations  on  the  Bulk  Hand-  174. 

ling  of  Grain  in  California.  178. 

Irrigation   Practice  in  Growing  Small  179. 

Fruit  in  California. 


87. 
111. 

113. 


127. 
129. 
136. 

144. 
151. 


154. 


Bovine  Tuberculosis. 

Control  of  the  Pear  Scab. 

Lettuce  Growing  in  California. 

Potatoes  in  California. 

Small  Fruit  Culture  in  California. 

Fundamentals   of   Sugar   Beet   Culture 

under  California  Conditions. 
The  County  Farm  Bureau. 
Feeding  Stuffs  of  Minor  Importance. 
Fertilizing  California  Soils  for  the  1918 

Crop. 
Wheat  Culture. 
The   Construction    of   the   Wood-Hoop 

Silo. 
Farm  Drainage  Methods. 
The  Packing  of  Apples  in  California. 
Factors    of    Importance    in    Producing 

Milk  of  Low  Bacterial  Count. 


CIRCULARS — (Continued) 


of 


in 


No. 

184.  A  Flock  of  Sheep  on  the  Farm. 

190.  Agriculture  Clubs  in  California. 

193.  A  Study  of  Farm  Labor  in  California. 

198.  Syrup  from  Sweet  Sorghum. 

199.  Onion  Growing  in  California. 

202.  County   Organizations   for  Rural   Fire 

Control. 

203.  Peat  as  a  Manure  Substitute. 
205.  Blackleg. 

208.  Summary  of  the  Annual  Reports  of  the 

Farm  Advisors  of  California. 

209.  The  Function  of  the  Farm  Bureau. 

210.  Suggestions  to  the  Settler  in  California. 
212.   Salvaging  Rain-Damaged  Prunes. 

214.  Seed  Treatment  for  the  Prevention 

Cereal  Smuts. 

215.  Feeding  Dairy  Cows  in  California. 
217.  Methods  for  Marketing  Vegetables 

California. 

219.  The  Present  Status  of  Alkali. 

220.  Unfermented  Fruit  Juices. 

228.  Vineyard  Irrigation  in  Arid  Climates. 

230.  Testing  Milk,    Cream,   and   Skim  Milk 

for  Butterfat. 

231.  The  Home  Vineyard. 

232.  Harvesting    and    Handling    California 

Cherries  for  Eastern  Shipment. 

233.  Artificial  Incubation. 

234.  Winter  Injury  to  Young  Walnut  Trees 

during  1921-22. 

235.  Soil  Analysis  and  Soil  and  Plant  Inter- 
relations. 

236.  The  Common  Hawks  and  Owls  of  Cali- 

fornia   from   the    Standpoint   of    the 
Rancher. 

237.  Directions  for  the  Tanning  and  Dress- 

of  Furs. 

238.  The  Apricot  in  California. 

239.  Harvesting  and  Handling  Apricots  and 

Plums  for  Eastern  Shipment. 

240.  Harvesting    and    Handling    Pears   for 

Eastern   Shipment. 

241.  Harvesting  and  Handling  Peaches  for 

Eastern  Shipment. 

242.  Poultry  Feeding. 

243.  Marmalade  Juice  and  Jelly  Juice  from 

Citrus  Fruits. 

244.  Central  Wire  Bracing  for  Fruit  Trees. 


No. 

245. 
247. 
248. 

249. 
250. 

251. 


252. 
253. 
254. 

255. 

256. 
257. 
258. 
259. 
260. 

261. 
262. 
263. 
264. 

265. 
266. 

267. 

268. 

269. 
270. 
271. 
272. 

273. 
275. 

276. 
277. 

278. 


Vine  Pruning  Systems. 

Colonization  and  Rural  Development. 

Some  Common  Errors  in  Vine  Pruning 
and  Their  Remedies. 

Replacing  Missing  Vines. 

Measurement  of  Irrigation  Water  on 
the  Farm. 

Recommendations  Concerning  the  Com- 
mon Diseases  and  Parasites  of 
Poultry  in  California. 

Supports  for  Vines. 

Vineyard  Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter  Egg  Production. 

Leguminous  Plants  as  Organic  Fertil- 
izer in  California  Agriculture. 

The  Control  of  Wild  Morning  Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning  Deciduous  Fruits. 

Pear  By-products. 

A  Selected  List  of  References  Relating 
to  Irrigation  in  California. 

Sewing  Grain   Sacks. 

Cabbage  Growing  in  California. 

Tomato  Production  in  California. 

Preliminary  Essentials  to  Bovine  Tuber- 
culosis Control. 

Plant  Disease  and  Pest  Control. 

Analyzing  the  Citrus  Orchard  by  Means 
of  Simple  Tree  Records. 

The  Tendency  of  Tractors  to  Rise  in 
Front;  Causes  and  Remedies. 

Inexpensive  Lavor-saving  Poultry  Ap- 
pliances. 

An  Orchard  Brush  Burner. 

A  Farm  Septic  Tank. 

Brooding  Chicks  Artificially. 

California  Farm  Tenancy  and  Methods 
of  Leasing. 

Saving  the  Gophered  Citrus  Tree. 

Marketable  California  Decorative 
Greens. 

Home  Canning. 

Head,  Cane,  and  Cordon  Pruning  of 
Vines. 

Olive  Pickling  in  Mediterranean  Coun- 
tries. 


The  publications  listed  above  may  be  had  by  addressing 

College  of  Agriculture, 

University  of  California, 

Berkeley,  California. 


12m-3,'25 


